Mechanism for notching piano-sounding-board bridges.



I H. e. & A. P. OSTERBERG. MECHANISM F013- NOTGHING PIANO SOUNDING BOARD BRIDGES.

APPLICATION FILED FEB. 25, 1908. Patented'oct. 20

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H. G. & A. P. OSTERBERG. MEGHANISM FOR NOTGHING PIANO SOUNDING BOARD BRIDGES. APPLICATION FILED F3125, 1908.

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UNITED STATES PATENT OFFICE.

HANS G. OSTERBERG AND AUGUST F. OSTERBERG, OF GREEN SBURG, PENNSYLVANIA, ASSIGNORS TO H. KLEBER & BROTHER CO. INCORPORATED, OF PITTSBURG, PENN- SYLVANIA.

Specification of Letters Patent.

Patented Oct. 20, 1908.

Application filed February 25, 1908. Serial No. 417,760.

To all whom it may concern:

Be it known that we, HANs Gr. OSTERBERG and AUGUsT F. OSTERBERG, residing at Grecnsburg, in the county of Westmoreland and State of Pennsylvania, have invented a new and Improved Mechanism for N otching Piano'Sounding-Board Bridges, of which the following is a specification.

In the finishing of the bridge members that are glued onto piano backs, the said membersare formed with a series of arbitrarily arranged notches that form seats for holding the piano strings from vibrating. Usually these notches are cut by hand.

The purpose of our invention is to provide a. simple, compact and effective mechanism whereby the operation of cutting the notches in the piano bridge can be accurately, expeditiously and conveniently accomplished, and with the said object and other objects in view and hereinafter referred to, our invention comprehends, in its generic nature, an adjustable or traveling carriage upon which is mounted a cutting mechanism and a piano back support movably mounted relatively to the cutting mechanism whereby it can be shifted, step by step, to bring the bridge pieces on the piano back into proper position with respect to the cutting mechanism for being notched.

. In its more subordinate features our invention consists in certain details of construction and peculiar combination of parts, all of which will be hereinafter fully described, specifically pointed out in the ap pended claims and illustrated in the accompanying drawings, in which Figure 1, is an end elevation of our improved mechanism, the truck being in'position with a piano back mounted thereon with one of its bridge members in position to be engaged by the cutting mechanism. Fig. 2, is a similar view of the cutting mechanism as seen from the opposite end. Fig. 3, is a longitudinal section of the truck. Fig. 4, is a cross section of the carrier supporting bracket and the gage taken substantially on the line 4.-4 on Fig. 1, the cutter carrier devices being shown in end elevation. Fig. 5, is a perspective view of the carrier and eccentrically mounted combined saw and cutter device. Fig. 6, is a similar view of the bracket, the feed screw and the gage mounted thereon. Fig. 7, is a diagram showing a portion of the piano bridge notched.

In the practical construction, our invention comprises a swinging arm 4, suitably formed of metal, the inner end of which terminates in an apertured head 40 that fits between the bifurcated bracket 41 in such manner that the said arm 4 can be swung up against the supporting post or wall A when not in use, the said inner end of the arm 4 also having a pendent heelportion 42 that abuts the post and serves to hold the arm 4 to a true horizontal position when it is set for use as clearly shown in Figs. 1 and '2, by reference to which it will be also seen that the heel portion 42 is apertured for receiving the bolt 43 that firmly secures the arm 4 to the post. The outer end of the arm 4 has a twopart laterally projected head 44 formed with an aperture 45 for receiving and rotatably supporting the outer end 50 of a feed screw 5, the inner end of which is rotatably held in a bearing 41 on a bracket 41, the outer end of the said screw also having a hand wheel 6 for manipulating, as clearly shown in the drawing.

The arm 4 has a longitudinal groove 46 in its under side, dovetailed in cross section and in which is slidably mounted a dove tailed head 30 of the carrier frame 3 that has a lateral bearing 31 having an internal screw-way 32 for engaging the feed screw 5 in such manner that the turning of the screw 5 in opposite directions will feed the carrier 3 back and forth in the longitudinal plane of the arm 4, for purpose presently explained.

As best shown in Fig. 5 the carrier 3 has a pendent bifurcated portion 33 in which is adjustably mounted a yoke 34 and in the said yoke is eccentrically mounted a bearing 34 for the shaft 1 upon which the cutting devices are mounted.

The cutting devices comprise a saw 2 and a chisel like cutter 20, the said saw and chisel being combined into a single rotary cutter and with the saw and cutter teeth in circumferential alinement, as clearly shown in Figs. 4 and 5.

The shaft 1 at one end carries a belt pulley at and a bearing member 34 at the other end, which carries an arm 7, the outer end of which has a grooved pulley 8 that engages the under side of the gage member 9,

whose front end is adjustably connected to the lateral bearing 14 of the arm 4: and Whose inner end is adjustably connected with the member 11 of the bracket 41 before referred to. By adjustably mounting the gage 9 it can be set up or down relatively to the work being operated on so to shift the cutter mechanism to cut the notches the depth desired, which adjustment is effected through the medium of the arm 7 turning, the eccentric bearing within the yoke 34: so as to raise and lower the cutter shaft 1.

10 designates a spring joined with the arm 7 and the carrier frame for holding the pulley 8 up against the gage 9.

The rotary motion is imparted to the cutter mechanism by an endless drive belt that takes around the main drive pulley 11 journaled on the post A and which is driven by a motor or engine belt 11 The drive belt passes from the pulley 11 to a pulley 12 on the outer end of the arm 4: back to a pulley 13 on the carrier and thence over the cutter shaft pulley a and back to pulley 11.

For conveniently and accurately feeding the bridge members to the cutting mechanism and adjusting the same step by step and also for easily mounting the piano back on which the bridges are glued, we have provided a special form of truck arranged for cooperating with the cutter mechanism, and this truck, the construction of which is clearly shown in Figs. 1 and 3, consists of a main frame C having legs, each carrying a grooved wheel 0 for riding the tracks 1515 that extend at right angles to the cutter mechanism, the reason for which will presently appear.

The table 16 receives and rotatably supports another table section 18, the upper face of which is properly inclined for supporting the piano back, (see Fig. 1), it having an angle bracket 18 at one end that forms a rest for one end of the said piano back.

The table 18 is slidably mounted on the table 16 and is held for connection with the said table 16 by the hooks 30 that are pivotally connected to the opposite ends of the table 16 and engage studs 19 on the table 18 as clearly understood from Fig. 1 which shows the three positions'that the table 18 is adjusted to during the operation of placing the piano back into position to be operated on.

From the foregoing, taken in connection with the accompanying drawings, the complete construction and manner in which our invention is manipulated will be readily apparent. T o operate the same the workman first shifts the table outwardly until it tilts to the position #1, it being now held from separating from the table 16 by the hooks 30*. The piano back is then placed on the upright table 18, after which the said table is tilted to the position #2. It is then slid back to the third or full line position ready for being operated upon. The operator now places the left hand on the truck and with the right hand manipulates the hand screw 6 and causes the cutting device to approach and cut the notch in the bridge a. The cutting mechanism being then fed back, the operator moves the truck C forward the required distance for the next notch, after which the cutting operation is repeated and this is kept up until the full number of notches have been cut in the bridge a. The table 18 is then pulled towardthe operator until the stud pins engage the hooks 30 when it is again turned down to the first position. The piano back is then taken off.

Having thus described our invention, what we claim and desire to secure by Letters Patent, is

1. A mechanism of the character stated which comprises a suitable support, a frame hingedly sustained thereon for projecting in the horizontal plane, a carrier reciprocatably mounted on the said frame to move in the longitudinal direction thereof, a rotary cutter mounted on the carrier, adjustable means on the carrier for setting the cutting edge of the cutter and traveling table for supporting the object to be out, said table having movement in a direction transverse to the direction of movement of the cutter carrier.

2. In a means for cutting bridge members of piano backs, the combination with a r0- tary cutter;'of a table comprising a horizontally rotatable top, a supplemental top mounted thereon and slidable with respect to the rotatable top, said slidable member having a bracket at one end to form a rest for the piano back and means on the supplemental top and the main table for limiting the outward sliding of the supplemental table and for tilting it to a vertical position.

In a means for notching bridge members on piano backs, the combination with a cutting mechanism; of a supporting means, comprising a table transversely adjustable with respect to the cutting mechanism, said tableincluding a rotary top, hook members pivotally connected to the opposite ends of the said top, a supplemental table top section slidably mounted on the rotatable top and having projecting studs at the opposite ends for cooperating with the pivoted hooks on the main table and. having a bracket piece at one edge for sustaining the piano back, all being arranged substantially as shown and for the purposes described.

4. The combination with means for sus- 1 taining a piano back bridge in position for cutting; a support, an arm hinged to the support to swing to the horizontal plane over the back sustaining means, a carrier reciprocatably mounted on the said arm, a

rotary cutter having a. shiftable bearing on the carrier, a gage adjustably mounted on the support and a member connected with the shiftable bearing of the cutter for engaging the adjustable gage, for the purposes specified.

5. In a mechanism for the purposes stated, the combination witl a suitable support and a table for sustalning the piano back in position to be operated on; of an arm projected horizontally from the said. support over the piano back sustaining means, a carrier reciprocably mounted on the said arm, a rotary cutter eccentrically mounted on the carrier, a gage adjustably connected to the arm and a means that cooperates with the said gage and with the eccentric bearing .of the rotary cutter for adjusting the cutting edge of the cutter with respect to the work to be operated on.

6. The combination of a horizontal bar 4, a feed screw mounted in the said bar, gage member 9 adjustably mounted on the said bar a, a carrier 3 mounted on the feed screw, eccentric bearings mounted on the carrier, a rotary cutter whose shaft is mounted in the eccentric bearings, an arm 7 the roller 8 pivotally connected with the eccentric bearings and a spring for holding the roller in contact with the gage 9.

7 The combination of a horizontal bar, a feed screw mounted in the said bar, gage member adjustably mounted on the said bar, a carrier mounted on the feed screw, eccentric bearings mounted on the carrier, a rotary cutter whose shaft is mounted in the eccentric bearings, an arm carrying a roller, pivotallyconnected with the eccentric bearings and a spring for holding the roller in contact with the gage, and a table movable at right angles to the direction of the movement of the cutter carriage for sustaining the piano back in position to be engaged by the cutting mechanism, all being arranged substantially as shown and for the purposes described.

HANS G. OSTERBERG. AUGUST F. OSTERBERG.

Witnesses FRED W. TUNKS, W. A. KUNKLE. 

